The Soviet 160 mm Mortar M1943 was a smoothbore breech loading heavy mortar which fired a massive 160 mm bomb. The M1943 (also called the MT-13) was the heaviest mortar used by Soviet troops in World War II. Around 535 of these weapons were fielded with Soviet forces during the war. It was replaced in Soviet service after World War II by the M-160 mortar of the same caliber.